I'll be the first to admit that my mechanical knowledge is somewhat lacking and that I need to turn to others for advice.
I took the Fury to the Mid-Atlantic Mopar Meet at Mason-Dixon Dragway yesterday. Since M-D is 75 miles from home and I'd only driven the car a little since I topped it off a couple weeks ago, I figured I'd gas it up at the Sheetz near the track before I headed home. It took 7.11 gallons after having been driven only 89 miles.
Now, this car has never gotten stellar gas mileage, with the all-time high being, I think, 17.6 mpg. Still, I doubt the 14 miles of running around town would be enough to negate the 75 miles of highway driving and drag the average down to 12.5 mpg. That's 440 Magnum mileage, and I'm only running a 318 with a 904 and 3.23 gears.
It has 192,600 miles on it. The carb is the original 2-barrel. It has MP electronic ignition with the orange box. The plugs were installed in 2001, which means they have maybe 3000 miles on them. The wires are from 1995, I believe, with about 15k on them. It currently has Valvoline Max Life 20W-50 oil in it. It has the stock air cleaner and manifolds with 2-1/4" dual exhaust. I've been running 87 octane in it since 92 cracked $2/gal here, whenever that was, and I'm not really hearing any valvetrain noise other than one lifter that occasionally gets noisy (it did that on 92, too).
I'm going to pull the plugs and see how they look, and I probably ought to replace those 11-year-old wires, too. Any other suggestions? The thought that it may be past time to tear into the engine has occurred to me, as well as the thought that finding another 318 with, oh, 100-110k fewer miles on it would be a sensible way to go.
Joined: Tue Oct 11 2005, 01:33AM
Location: Calgary, Alberta
Posts: 5893
To be honest, it doesn't sound like you drive it enough! You really can't tell much with a bunch of short trips and a short highway run. With your numbers the difference between 12.5 mpg and 17.5 mpg is less than 2 gal of gas. You probably burned half of that just getting off the choke on your short trips!
Take her out and stretch her legs and if you've got any ignition or carb problems you'll feel it.
There is a huge difference between city short trips and highway and that became very clear to me when I got my Crown Victoria with it's computerized dash display. It tells me all kinds of stats both averaged and instant. In the city the car gets typically just under 20 mpg but on a long (500-600 mile) trip it soars to nearly 32 mpg depending on how heavy footed I am. Considering that both the ignition and fuel settings are continuously being optimized, I was surprised how much city driving kills the efficiency. In the winter when longer engine heat ups are the norm, fuel efficiency in the city drops to near 15 mpg.
One thing to watch for are those $19.95 bargain plug wires,the voltage that you're electronic ign. puts out will destroy them.They may look good on the outside but on the inside the cores could be shot.Same as the cap,get a Blue Steak premium or Accel cap and rotor,they have closer tolerances and far superior materials,for only a few dollars more.I had over 250 thou. on a 318 and it would use a quart every 15-200 miles and still purred.Fuel mileage drpped off suddenly and i rebuilt the carb with a generic kit,it got worse.I found an original kit with a pound of dust on it that my friend had kicking around and it picked right up.The moral of this story is to try and use quality parts,and they will pay you back in short order.Glen
Joined: Sat Dec 10 2005, 04:28PM
Location: United States
Posts: 4954
Hey Paul I agree with all. But there are other factors too
What kind of shape are the points or is it pointless ignition now? Timing chain, They're good on a 318 for about 100K, Internal condition of the carb, carboned cylinders, sticky rings. . . . The list is endless.
If you are interested, I will have a running 69 318 available in late August. Since you are only in Maryland, you're about 3 hours away. The engine has about 70K on it as the trans. Actually it's an engine and trans. The car rotted away around the engine. I can have the engine and trans for 100 Bucks. I am buying the rear. It's in PA, but I can truck it back to here and have a hoist. I can even pressure wash it for you. I heard it running last fall.
Joined: Tue Oct 11 2005, 11:01AM
Location: Central Iowa
Posts: 227
Another thing to consider is if the car was level when it was at the pump. This could have easily accounted for a 2 gallon difference that you may not notice on the gas gage.
Thanks for all the input, everybody. The 20W-50 oil wouldn't have been my first choice, SportFury440. I had been running 10W-40, but the last time I took it to the oil-change place (I know, I should do it myself, but my driveway's a disaster and disposal is a hassle) they didn't have any 10W-40 Max Life. It had been a long time since my last oil change and I was about to drive it 150 miles, and I wanted fresh oil in it. One thing I have noticed is that, with the heavier oil, I no longer see the oil light flickering at idle after I've been driving on the highway for a while (the oil pump was replaced 12,000 miles ago, in early '97). It has a Mopar Performance electronic ignition kit, 71f3, so no more points to wear out. I'm thinking about springing for new plugs, wires, cap and rotor for now, and may replace the hoses and thermostat as well--not that those impact the mileage, but they're all pretty old.
71f3, I'm really tempted by that 70k-mile engine. You say you're three hours from me. Three hours in which direction?
Fury440, you may have a point about not driving it enough. It's worth noting that I put 8000 miles on it from August '94 to January '97 and have only put about 600 miles on it each of the last four years. I don't drive it to work, I don't run it in the rain and it usually sits from Christmas until March waiting for the roads to be free of salt. I also parked it for a couple months last fall because of the post-Katrina gas spike. The roundtrip to Mason-Dixon is 150 miles and Carlisle is 220, so there's over half the annual mileage just on those two trips. The rest is "Hey, it's a nice day" drives and going to the local cruise night.
Paul 300, I generally try to have it nose-down when I fill the tank so there's minimal spillage when it's full--sometimes I can't arrange that, though. My gas gauge doesn't work, something I've been meaning to fix for years, so I generally watch the mileage to decide when to fill up--I used to go 200 miles, but that got too expensive so I dropped back to 150 and then 100 (I hate seeing the amount pass $30.00). It's very possible that it wasn't really full on one or more previous fillups.
What a lot of these come down to is this: I love owning a classic car, I love driving a classic car, but I am one cheap so-and-so.